Adrenal Insufficiency Related to Anti-Programmed Death-1 Therapy

Adrenal insufficiency is one of the adverse events (AEs) associated with anti-programmed death-1 (PD1) therapy. Delaying diagnoses can lead to serious conditions. It is necessary to elucidate detailed clinical features of these AEs. Patients treated with anti-PD-1 monotherapy or in combination with anti-cytotoxic T cell lymphocyte-4 therapy at our hospital from January 2013 to December 2016 were identified. The patients' clinical characteristics and laboratory and radiologic findings were collected. Adrenal insufficiency occurred in 3% of the patients. All patients were male. At the onset of symptoms, eosinophilia (>500/μl) was observed in four cases. Eosinophilia was observed more than a month before onset of symptoms in three cases. Other pituitary hormones remained relatively stable. Radiological evidence of pituitary inflammation was detected only in one case. Most anti-PD1-related adrenal insufficiency cases involved an isolated ACTH deficiency. Eosinophilia may be an early indicator before the onset of symptoms.